1. Field of the Invention
The present invention relates to a microwave dryer for a washing machine, and in particular to an improved microwave dryer for a washing machine which is capable of implementing a washing and drying operation in a washing tub of a microwave dryer using microwaves.
2. Description of the Conventional Art
Generally, when a washing and drying operation for laundry is finished, a user operates a dryer operation key for a drying operation for the laundry. FIG. 1 illustrates a conventional heating type dryer for a washing machine. As shown therein, as a fan motor 19a installed at an upper portion of a main body 1a for drying laundry in a washing tub 4a of the main body 1a is operated, air is flown into the interior of the washing tub 4a through a dryer duct 18a. At this time, the air flown thereinto is heated by a heater 26 installed at an upper portion of the dryer duct 18a and the heated dry air is flown into the interior of the washing tub 4a. Here, the high temperature air serves to evaporate moisture of the laundry in the washing tub 4b for thereby dehydrating the laundry.
In addition, since the heated air is continuously provided thereinto by the fan motor 19a, moisture is evaporated from the laundry in the washing tub 4b, and the air containing moisture is flown to a condensing duct 23a. In the condensing duct 23a, moisture contained in air is condensed for thereby forming water. The thusly formed water is discharged to the outside of the main body 1a through a drainage hose 27. The dehydrated air is heated again by the heater 26 and is transferred into the interior of the washing tub 4a through the dryer duct 18a. The above-described operations are continuously repeated for thereby fully evaporating moisture of the laundry.
In addition, the method and apparatus for operating a microwave dryer disclosed in U.S. patent Ser. No. 5,463,821 is capable of more quickly drying the laundry compared to the heating type dryer and preventing any damage of the laundry. When the washing operation is finished, the laundry is dehydrated using microwaves generated by a magnetron. The above-described apparatus will be explained in more detail with reference to FIGS. 2 through 4.
As shown therein, laundry is inputted into a drying chamber (not shown) installed in the interior of a drum 28 of the main body 1b by opening a door 2a installed in the front portion of the main body 1b, and then a drying operation key is operated, so that the drying operation for the laundry is started.
Therefore, microwaves generated by the magnetron 30 installed in the interior of baffles 29 formed on the inner circumferential surface of the drum 28 pass through a plurality of through holes 29a formed in the baffles 29 for thereby drying the laundry in the drying chamber of the drum 28. At this time, a plurality of holes are formed on the lateral walls of the drum 28, so that air is flown into the drying chamber of the drum 28 therethrough, and the thusly flown air servers to cool the magnetron 30 installed in the interior of the baffles 29. In addition, a power line 31 is installed on a lateral wall of the drum 28 for continuously supplying an electric power even when the drum 28 is rotated during the drying operation. The drum 28 is rotated by the motor 32 installed below the main body 1b, and the microwaves generated by the magnetron 30 pass through the holes 29a formed in the baffles 29 for thereby dehydrating the laundry in the drum 28. The air flown into the drying chamber through the holes formed on the lateral walls of the drum 28 contain much moisture, and then are discharged to the outside of the main body 1b through the holes 33 formed at the rear center portion of the drum 28. The above-described operations are repeated.
However, in the conventional heating type dryer for a washing machine, air is heated by the heater 26, and the thusly heated air servers to evaporate moisture contained in the laundry. Namely, the conventional heating type dryer is directed to an indirect heating method. In this case, much heat exchanging loss occurs during the washing and drying operations, so that the drying efficiency is decreased, and the drying time is extended. In order to effectively evaporate moisture from the creased portions of the laundry, the surface temperature of the laundry should be increased for thereby damaging the laundry.
In addition, in the conventional microwave dryer for a washing machine, the magnetron 30 is directly disposed in the interior of the baffles 29 of the inner circumferential surface of the drum 28. As the drum 28 is rotated, the magnetron 30 emits microwaves. The electric power of over 4000 Volts supplied to the magnetron 30 in the direct contact method may make fire due to spark. In addition, since a leakage between the drum 28 and the magnetron 30 and a high speed rotation are not implemented, it is impossible to effectively implement a washing and drying function. After the washing operation of the laundry is finished, the laundry is manually moved into the drying chamber of the dryer for thereby causing much inconvenience.